<script setup>
import { ref, watch } from 'vue'
import { useMouseInElement } from '@vueuse/core'

// props适配图片列表
defineProps({
   imageList: {
      type: Array,
      default: () => []
   }
})
// // 图片列表
// const imageList = [
//    "https://yanxuan-item.nosdn.127.net/d917c92e663c5ed0bb577c7ded73e4ec.png",
//    "https://yanxuan-item.nosdn.127.net/e801b9572f0b0c02a52952b01adab967.jpg",
//    "https://yanxuan-item.nosdn.127.net/b52c447ad472d51adbdde1a83f550ac2.jpg",
//    "https://yanxuan-item.nosdn.127.net/f93243224dc37674dfca5874fe089c60.jpg",
//    "https://yanxuan-item.nosdn.127.net/f881cfe7de9a576aaeea6ee0d1d24823.jpg"
// ]
// 小图切换大图显示
const activeIndex = ref(0)
const enterhandler = (i) => {
   activeIndex.value = i
}
// 获取鼠标相对位置
const target = ref(null)
const { elementX, elementY, isOutside } = useMouseInElement(target)
// 控制滑块跟随鼠标移动(监听x/y值变化，一旦变化，重新设置left/top值)
const left = ref(0)
const top = ref(0)
const positionX = ref(0)
const positionY = ref(0)
watch([elementX, elementY, isOutside], () => {
   // 如果鼠标没有移入到盒子里面 跳过后面逻辑
   if (isOutside.value) return
   // 有效范围内控制滑块距离
   // 横向
   if (elementX.value > 100 && elementX.value < 300) {
      left.value = elementX.value - 100
   }
   // 纵向
   if (elementY.value > 100 && elementY.value < 300) {
      top.value = elementY.value - 100
   }

   // 边界距离控制
   if (elementX.value < 100) { left.value = 0 }
   if (elementX.value > 300) { left.value = 200 }

   if (elementY.value < 100) { top.value = 0 }
   if (elementY.value > 300) { top.value = 200 }

   // 控制大图显示
   positionX.value = -left.value * 2
   positionY.value = -top.value * 2
})
</script>


<template>
   <div class="goods-image">
      <!-- 左侧大图-->
      <div class="middle" ref="target">
         <img :src="imageList[activeIndex]" alt="" />
         <!-- 蒙层小滑块 -->
         <div class="layer" v-show="!isOutside" :style="{ left: `${left}px`, top: `${top}px` }"></div>
      </div>
      <!-- 小图列表 -->
      <ul class="small">
         <li v-for="(img, i) in imageList" :key="i" @mouseenter="enterhandler(i)" :class="{ active: i === activeIndex }">
            <img :src="img" alt="" />
         </li>
      </ul>
      <!-- 放大镜大图 -->
      <div class="large" :style="[
         {
            backgroundImage: `url(${imageList[activeIndex]})`,
            backgroundPositionX: `${positionX}px`,
            backgroundPositionY: `${positionY}px`,
         },
      ]" v-show="!isOutside"></div>
   </div>
</template>

<style scoped lang="scss">
.goods-image {
   width: 480px;
   height: 400px;
   position: relative;
   display: flex;

   .middle {
      width: 400px;
      height: 400px;
      background: #f5f5f5;
   }

   .large {
      position: absolute;
      top: 0;
      left: 412px;
      width: 400px;
      height: 400px;
      z-index: 500;
      box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
      background-repeat: no-repeat;
      // 背景图:盒子的大小 = 2:1  将来控制背景图的移动来实现放大的效果查看 background-position
      background-size: 800px 800px;
      background-color: #f8f8f8;
   }

   .layer {
      width: 200px;
      height: 200px;
      background: rgba(0, 0, 0, 0.2);
      // 绝对定位 然后跟随咱们鼠标控制left和top属性就可以让滑块移动起来
      left: 0;
      top: 0;
      position: absolute;
   }

   .small {
      width: 80px;

      li {
         width: 68px;
         height: 68px;
         margin-left: 12px;
         margin-bottom: 15px;
         cursor: pointer;

         &:hover,
         &.active {
            border: 2px solid $xtxColor;
         }
      }
   }
}
</style>